This relates to electronic devices with wireless circuitry, and more particularly, to techniques for using antennas in an electronic device so as to avoid potential interference.
Electronic devices such as cellular telephones include wireless circuitry. Input-output ports may be used to connect electronic devices with wireless circuitry to accessories. For example, many devices include ports to which a user may connect an audio-video accessory such as a display.
When a device communicates with an external accessory such as a display, high-speed data signals are transmitted and received by the device. As these high-speed signals pass through the input-output port of the device, circuitry that is adjacent to the input-output port may be affected. In particular, if an antenna is located within the vicinity of the input-output port, the antenna may pick up electromagnetic interference from the input-output port.
The electromagnetic interference may be sufficiently strong to disrupt normal device operation. For example, a cellular telephone receiver that is coupled to the antenna may be so overwhelmed with interference that the cellular telephone receiver will be unable to detect incoming cellular telephone calls or may drop an existing call.
It would therefore be desirable to be able to provide improved ways in which to avoid the effects of electromagnetic interference in a wireless electronic device that communicates using input-output ports.